Cutting tools and cutting inserts composed of cemented hard particles are employed in machining operations, such as, for example, cutting, drilling, reaming, countersinking, counterboring, milling, turning, grooving, threading, and tapping. As used herein, “cemented hard particles” and a “cemented hard particle material” refer to a material comprising relatively hard particles dispersed and cemented within a relatively soft metallic binder. An example of a cemented hard particle material is a cemented carbide material. Also as used herein, a “cemented” article is an article comprising a cemented hard particle material. A process for manufacturing cemented cutting tools may involve consolidating metallurgical powder (e.g., a mixture of hard particles and metal binder powder) to form a compact. The compact may be sintered to form a tool blank having a solid monolithic construction. After sintering, a cemented tool blank may be machined to form one or more cutting edges or other features of the particular cutting geometry desired on the tool.
Cemented cutting tools comprising hard particles cemented in a binder are industrially important because of the combination of tensile strength, wear resistance, and toughness that is characteristic of these materials. The hard particles may comprise, for example, carbides, nitrides, borides, silicides, or oxides of elements within groups IIIA, and IVB through VIB of the periodic table. An example is tungsten carbide. The binder may be a metal or metal alloy, for example, cobalt, nickel, iron or alloys of these metals. The binder cements the hard particles within a continuous and interconnected matrix.
The physical and chemical properties of cemented materials depend in part on the individual components of the metallurgical powders used to form the materials. The properties of cemented hard particle materials may depend upon the chemical composition of the hard particles, the average particle size and particle size distribution of the hard particles, the chemical composition of the binder, and the ratio of binder to hard particles in the substrate, for example.
Tungsten carbide hard particles cemented in a cobalt binder is a common cemented carbide material that finds utility in metalworking tools, such as, for example, turning tools and inserts, milling tools and inserts, drilling tools and inserts, threading tools and inserts, and grooving tools and inserts (collectively, “cutting tools”). As used herein, the term “cutting tools” includes monolithic cutting tools and inserts for modular cutting tools.